LeetCode： Jewels and Stones

Question

You’re given strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in S is a type of stone you have. You want to know how many of the stones you have are also jewels.

The letters in J are guaranteed distinct, and all characters in J and S are letters. Letters are case sensitive, so “a” is considered a different type of stone from “A”.

Example 1:

Input: J = "aA", S = "aAAbbbb"

Output: 3

Example 2:

Input: J = "z", S = "ZZ"

Output: 0

Solution

def num_jewels_in_stones(j, s)
  p jewel_list = j.split('')
  p stone_list = s.split('')
  count = 0

  jewel_list.map do |jewel|
    stone_list.map do |stone|
      if stone == jewel
        count += 1
      end
    end
  end
  count
end